title: Calcium ionophore polarizes ooplasmic segregation in ascidian eggs.
abstract: Calcium ionophore A23187 promotes ooplasmic segregation and orange crescent formation in eggs of the ascidian Boltenia villosa. When eggs were exposed to a gradient A23187 the orange crescent was induced to form in the region corresponding to the highest concentration of ionophore. This result is consistent with the hypothesis that a local increase in intracellular calcium polarizes cytoplasmic localization in the ascidian embryo.
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000001:Calcimycin / Q000494:pharmacology*; D002118:Calcium / Q000502:physiology*; D002451:Cell Compartmentation / Q000187:drug effects; D003593:Cytoplasm / Q000648:ultrastructure; D004305:Dose-Response Relationship, Drug; D005260:Female; D010063:Ovum / Q000187:drug effects* / Q000648:ultrastructure; D014561:Urochordata
chemical_list: D000900:Anti-Bacterial Agents; D000001:Calcimycin; D002118:Calcium